ADDC02812DA datasheet(15/20 Pages) AD

15 / 20 page

ADDC02812DA/ADDC02815DA

REV. A

–15–

CE102: This test measures emissions in the frequency range

between 10 kHz and 10 MHz. The measurements are made on

both of the input leads of the converter which are connected to

the power source through LISNs. The intent of this requirement

in the lower frequency portion of the requirement is to ensure

that the dc/dc converter does not corrupt the power quality

(allowable voltage distortion) on the power buses present on the

platform. At higher frequencies, the intent is to serve as a sepa-

rate control from RE102 on potential radiation from power

leads which may couple into sensitive electronic equipment.

Figure 14 shows the CE102 limit and the measurement taken

from the +VIN line. While the measurement taken from the

input return line is slightly different, both comfortably meet the

MIL-STD-461D, CE102 limit.

CS101: This test measures the ability of the converter to reject

low frequency differential signals, 30 Hz to 50 kHz, injected on

the dc inputs. The measurement is taken on the output power

leads. The intent is to ensure that equipment performance is not

degraded from ripple voltages associated with allowable dis-

tortion of power source voltage waveforms. Figure 10 shows a

typical audio susceptibility graph. Note that according to the

MIL-STD-461D test requirements, the injected signal between

30 Hz and 5 kHz has an amplitude of 2 V rms and from 5 kHz

to 50 kHz the amplitude decreases inversely with frequency to

0.2 V rms. The curve of the injected signal should be multiplied

by the audio susceptibility curve to determine the output ripple

at any frequency. When this is done, the worst case output

ripple at the frequency of the input ripple occurs at 5 kHz, at

which point there is typically a 25 mV peak-to-peak output

ripple.

It should be noted that MIL-STD-704 has a more relaxed

requirement for rejection of low frequency differential signals

injected on the dc inputs than MIL-STD-461D. MIL-STD-

704 calls for a lower amplitude ripple to be injected on the input

in a narrower frequency band, 10 Hz to 20 kHz.

CS114: This test measures the ability of the converter to operate

correctly during and after being subjected to currents injected

into bulk cables in the 10 kHz to 400 MHz range. Its purpose is

to simulate currents that would be developed in these cables due

to electromagnetic fields generated by antenna transmissions.

The converter is designed to meet the requirements of this test

when the current is injected on the input power leads cable.

Consult factory for more information.

CS115: This test measures the ability of the converter to oper-

ate correctly during and after being subjected to 30 ns long

pulses of current injected into bulk cables. Its purpose is to

simulate transients caused by lightning or electromagnetic

pulses. The converter is designed to meet this requirement

when applied to its input power leads cable. Consult factory for

more information.

CS116: This test measures the ability of the converter to oper-

ate correctly during and after being subjected to damped sinu-

soid transients in the 10 kHz to 100 MHz range. Its purpose is

to simulate current and voltage waveforms that would occur

when natural resonances in the system are excited. The con-

verter is designed to meet this requirement when applied to its

input power leads cable. Consult factory for more information.

RE101: This requirement limits the strength of the magnetic

field created by the converter in order to avoid interference with

sensitive equipment located nearby. The measurement is made

from 30 Hz to 100 kHz. The most stringent requirement is for

the Navy. Figure 15 shows the test results when the pickup coil

is held 7 cm above the converter. As can be seen, the converter

easily meets this requirement.

RE102: This requirements limits the strength of the electric

field emissions from the power converter to protect sensitive

receivers from interference. The measurement is made from

10 kHz to 18 GHz with the antenna oriented in the vertical

plane. For the 30 MHz and above range the standard calls for

the measurement to be made with the antenna oriented in the

horizontal plane, as well.

In a typical power converter system setup, the radiated emis-

sions can come from two sources: (1) the input power leads as

they extend over the two meter distance between the LISNs and

the converter, as required for this test, and (2) the converter

output leads and load. The latter is likely to create significant

emissions if left uncovered since minimal EMI filtering is pro-

vided at the converter’s output. It is typical, however, that the

power supply and its load would be contained in a conductive

enclosure in applications where this test is applicable. A metal

screen enclosure was therefore used to cover the converter and

its load for this test.

ADDC02812DA датащи(PDF) 15 Page - Analog Devices

ADDC02812DA датащи(HTML) 15 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

датащи скачать

ссылки URL